The air quality in Delhi, the capital territory of India, according to a WHO survey of 1,650 world cities, is the worst of any major city in the world. It also affects the districts around Delhi Air pollution in India is estimated to kill about 2 million people every year; it is the fifth largest killer in India.

The air quality of Delhi, Gurugram and Noida, which are part of the NCR (National Capital Region), was in the “very poor” category on Friday October 23, morning, according to the Central Pollution Control Board (CPCB) data.

The AQI (Air Quality Index) of Delhi was 365 at 8 a.m. on Friday and the values for Gurugram and Noida were 318 and 386 respectively. All three values are in the “red” category and it can cause “respiratory illness on prolonged exposure”, according to the CPCB.

An AQI between 0 and 50 is considered “good”, 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.

The AQI of Delhi and Gurugram was in the “poor” category and Noida’s was in the lower end of “very poor”, as per CPCB’s 4 p.m. bulletin on Thursday, which is an average of the past 24 hours. The Supreme Court appointed Environment Pollution (prevention and control) Authority (EPCA) on Friday said that it was closely observing the air quality around Delhi and National Capital Region (NCR) and directed the agencies to ensure vigilance on the ground against different sources of pollution.

Medical experts reiterated the need to curb pollution in order to mitigate Covid-19 risks. “There are several studies from across the world that show pollution certainly has an impact on Covid-19 related mortality. In Italy, there was 12% mortality in northern Italy as compared to 4.5% in the rest of the country.

Advising the people not to step out unless it was necessary, the Authority has asked people to wear a mask at all times and said that air quality may even turn ‘severe’ briefly on Saturday, depending on the wind direction.

Reasons of Winter Pollution in Delhi:

Every winter, Delhi’s air quality dips to a dangerous low due to many reasons, including the city’s geographic location, unfavourable weather, stubble burning and local sources of pollution.

Apart from the other pollution which are due to overpopulation, vehicular emissions and industries, following are the factors that make winter pollution severe:

Shifting of Jet Stream: The southward shift of subtropical jet stream happens causing a westward wind pattern in the northern part of India and thus spread of pollutants.

Stagnant Lower Level Winds: As the winter season sets in, dust particles and pollutants in the air become unable to move. Due to stagnant lower level winds, pollutants get locked in the air and affect weather conditions, resulting in smog.

Stubble Burning: It is a traditional practice in Punjab and Haryana to clean off the rice chaff to prepare the fields for winter sowing.

We know that Graded Response Action Plan (GRAP), devised by the Environmental Pollution Control Authority (EPCA) appointed by the Supreme Court of India, has not achieved its objective of reducing air pollution of Delhi-NCR. While stubble burning of rice crop during winter months contributes heavily (40-50 per cent) to air pollution, the pollution levels due to rest of the sources — road transport, construction/demolition activities, road sweeping, coal-based industries and power plants, burning of garbage/waste and diesel generators — have not been mitigated significantly enough.

Current values can cause respiratory illness on prolonged exposure.

Delhi’s air quality has dropped to the “poor” category on Friday and is likely to deteriorate further due to unfavourable meteorological conditions and a spike in farm fires.

The steps taken by the authorities to control air pollution:

The steps taken by the authorities under the Graded Response Action Plan have been both piecemeal and delayed. Innovative measures are needed to curb stubble burning and vehicular pollution.

The Delhi Pollution Control Committee (DPCC) has banned the use of diesel generators in the national capital region from Thursday under the Graded Response Action Plan (GRAP) as the air quality dipped to the “very poor” category.

Advising the people not to step out unless it was necessary, the Authority has asked people to wear a mask at all times and said that air quality may even turn ‘severe’ briefly on Saturday, depending on the wind direction.

Track the pollution level in your city:

“”System of Air Quality and Weather Forecasting and Research (SAFAR)” has informed us that we could be in ‘severe’ category tomorrow for some time. However, it is not certain if the wind direction will change for the better or worse on Sunday. So, we are observing the situation carefully. For the moment, our recommendation is that we must ensure enforcement on the ground to check all the sources of pollution. We are also reiterating the advice given to be safe from coronavirus that we should only go out when absolutely necessary and at all times wear masks,” said EPCA on Friday.

The Delhi Pollution control Committee (DPCC), meanwhile, also issued the directions to several agencies on Friday, asking for action to be stepped up on the ground, including sprinkling of water, carrying out mechanised sweeping and ensuring that no garbage burning takes place around the capital.

“As the air quality in Delhi has been deteriorating, we along with other agencies are intensifying our drive to control pollution level. We have asked the head of all agencies to strictly enforce Graded Response Action Plan (GRAP) measures,” said a senior DPCC official.